In recent years, because of global environmental problems such as depletion of energy sources, increase in carbon dioxide in the atmosphere and the like, a clean energy source is desired to be developed, especially, photovoltaic power generation that uses solar battery cells is developed as a new energy source, put into practical use and is on the way of development. As for the solar battery cell, conventionally, the mainstream is a solar battery module that has a structure in which on a light receiving surface of a monocrystalline or polycrystalline-electroconductive-type silicon substrate, a pn junction is formed by diffusing reverse electroconductive-type impurities; and a plurality of solar battery cells, in each of which electrodes are formed on the light receiving surface and a back surface of the silicon substrate, are connected to each other.
Besides, another solar battery cell is also widespread, in which an impurity layer that contains the same electroconductive impurities at a high density is formed on a back surface of one electroconductivity type silicon substrate, so that a high output due to a back-surface field effect is obtained. Moreover, a so-called back electrode-type solar battery cell is also developed, in which an electrode is not formed on a light receiving surface of a silicon substrate; instead, a P electrode and an N electrode are formed on a back surface of the silicon substrate.
Because the back electrode-type solar battery cell generally does not have an electrode on the light receiving surface, so that it is expected to obtain a high output compared with a solar battery cell that has an electrode on each of the light receiving surface and the back surface of the silicon substrate.
Because of this, a proposition is provided, in which the back electrode-type solar battery cells are connected to each other by means of a wiring board in which wirings are formed on an insulating base, so that the connection of the back electrode-type solar battery cells becomes easy and it is possible to reduce cell flaws (e.g., see patent document 1).